1. Field of the Invention
Embodiments of the present invention generally relate to a large area substrate processing system having a transfer robot.
2. Description of the Related Art
Thin film transistors (TFT) are commonly used for active matrix displays such as computer and television monitors, cell phone displays, personal digital assistants (PDAs), and an increasing number of other devices. Generally, flat panels comprise two glass plates having a layer of liquid crystal materials sandwiched therebetween. At least one of the glass plates includes one conductive film disposed thereon that is coupled to a power source. Power, supplied to the conductive film from the power source, changes the orientation of the crystal material, creating a pattern display.
With the marketplace's acceptance of flat panel technology, the demand for larger displays, increased production and lower manufacturing costs have driven equipment manufacturers to develop new systems that accommodate larger size glass substrates for flat panel display fabricators. Current glass processing equipment is generally configured to accommodate substrates up to about one square meter. Processing equipment configured to accommodate substrate sizes up to and exceeding 1½ square meters is envisioned in the immediate future.
Equipment to fabricate such large substrates represents a substantial investment to flat panel display fabricators. Conventional systems require large and expensive hardware. For example, the increase volume requires vacuum pumps having higher capacities while port sealing apparatus must be enhanced to accommodate larger sealing forces due to the larger passages needed to accommodate larger substrates. Additionally, due to their large capital costs, typical large substrate processing systems have many processing chambers coupled to a central transfer chamber in order to maximize process flexibility for a given tool foot print.
However, this increased equipment size and cost represents a substantial problem for fabricators having limited factory space available for such equipment. Moreover, fabricators seeking to perform a limited number of process steps are disadvantageously required to utilize equipment having capacities, process capability and size much greater than required to perform limited processing on large area substrates.
Therefore, there is a need for compact processing equipment for large area substrates.